I am posting this in case someone does not know of this.
If I had not seem it myslef,, I'd still be skeptical, (from reading on other
groups)

you use Koi Clay!!

yesterday I noticed I had hundreds of strands of this stuff growing, ( there
were only a couple LONG pieces last week, but I ignored them), so I figured
I better do 'something'.
I put in Koi Clay last night & *WOW* it has all dissapeared! I am stunned!!
(other ponders say it takes several days to get rid of it)

it was suggested for 2 Tablespoons per thousand gal. ( I only put in 1 T.
per thousand) and have read different directions as to every day or every
other day.

Koi Clay is supposed to be very beneficial for your pond ( besides the
Koi).

(I bought mine last year , but it was packed away all winter, ebay is a good
source, Calcium Bentonite)